// Purpose: wxGIFDecoder, GIF reader for wxImage and wxAnimation
// Author: Guillermo Rodriguez Garcia <guille@iies.es>
// Version: 3.04
-// RCS-ID: $Id$
// Copyright: (c) Guillermo Rodriguez Garcia
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
#ifndef WX_PRECOMP
#include "wx/palette.h"
+ #include "wx/intl.h"
+ #include "wx/log.h"
#endif
#include <stdlib.h>
#include <string.h>
#include "wx/gifdecod.h"
+#include "wx/scopedptr.h"
+#include "wx/scopeguard.h"
+enum
+{
+ GIF_MARKER_EXT = '!', // 0x21
+ GIF_MARKER_SEP = ',', // 0x2C
+ GIF_MARKER_ENDOFDATA = ';', // 0x3B
+
+ GIF_MARKER_EXT_GRAPHICS_CONTROL = 0xF9,
+ GIF_MARKER_EXT_COMMENT = 0xFE,
+ GIF_MARKER_EXT_APP = 0xFF
+};
+#define GetFrame(n) ((GIFImage*)m_frames[n])
//---------------------------------------------------------------------------
// GIFImage
// def ctor
GIFImage();
- unsigned int w; /* width */
- unsigned int h; /* height */
- unsigned int left; /* x coord (in logical screen) */
- unsigned int top; /* y coord (in logical screen) */
- int transparent; /* transparent color index (-1 = none) */
- wxAnimationDisposal disposal; /* disposal method */
- long delay; /* delay in ms (-1 = unused) */
- unsigned char *p; /* bitmap */
- unsigned char *pal; /* palette */
- unsigned int ncolours; /* number of colours */
-
- DECLARE_NO_COPY_CLASS(GIFImage)
+ unsigned int w; // width
+ unsigned int h; // height
+ unsigned int left; // x coord (in logical screen)
+ unsigned int top; // y coord (in logical screen)
+ int transparent; // transparent color index (-1 = none)
+ wxAnimationDisposal disposal; // disposal method
+ long delay; // delay in ms (-1 = unused)
+ unsigned char *p; // bitmap
+ unsigned char *pal; // palette
+ unsigned int ncolours; // number of colours
+ wxString comment;
+
+ wxDECLARE_NO_COPY_CLASS(GIFImage);
};
+wxDECLARE_SCOPED_PTR(GIFImage, GIFImagePtr)
+wxDEFINE_SCOPED_PTR(GIFImage, GIFImagePtr)
//---------------------------------------------------------------------------
void wxGIFDecoder::Destroy()
{
wxASSERT(m_nFrames==m_frames.GetCount());
- for (size_t i=0; i<m_nFrames; i++)
+ for (unsigned int i=0; i<m_nFrames; i++)
{
GIFImage *f = (GIFImage*)m_frames[i];
free(f->p);
// This function was designed by Vaclav Slavik
-bool wxGIFDecoder::ConvertToImage(size_t frame, wxImage *image) const
+bool wxGIFDecoder::ConvertToImage(unsigned int frame, wxImage *image) const
{
unsigned char *src, *dst, *pal;
unsigned long i;
int transparent;
- /* just in case... */
+ // just in case...
image->Destroy();
- /* create the image */
+ // create the image
wxSize sz = GetFrameSize(frame);
image->Create(sz.GetWidth(), sz.GetHeight());
+ image->SetType(wxBITMAP_TYPE_GIF);
- if (!image->Ok())
+ if (!image->IsOk())
return false;
pal = GetPalette(frame);
dst = image->GetData();
transparent = GetTransparentColourIndex(frame);
- /* set transparent colour mask */
+ // set transparent colour mask
if (transparent != -1)
{
for (i = 0; i < GetNcolours(frame); i++)
image->SetPalette(wxPalette(GetNcolours(frame), r, g, b));
#endif // wxUSE_PALETTE
- /* copy image data */
+ // copy image data
unsigned long npixel = sz.GetWidth() * sz.GetHeight();
for (i = 0; i < npixel; i++, src++)
{
*(dst++) = pal[3 * (*src) + 2];
}
+ wxString comment = GetFrame(frame)->comment;
+ if ( !comment.empty() )
+ {
+ image->SetOption(wxIMAGE_OPTION_GIF_COMMENT, comment);
+ }
+
return true;
}
// Data accessors
//---------------------------------------------------------------------------
-#define GetFrame(n) ((GIFImage*)m_frames[n])
-
-
// Get data for current frame
-wxSize wxGIFDecoder::GetFrameSize(size_t frame) const
+wxSize wxGIFDecoder::GetFrameSize(unsigned int frame) const
{
return wxSize(GetFrame(frame)->w, GetFrame(frame)->h);
}
-wxPoint wxGIFDecoder::GetFramePosition(size_t frame) const
+wxPoint wxGIFDecoder::GetFramePosition(unsigned int frame) const
{
return wxPoint(GetFrame(frame)->left, GetFrame(frame)->top);
}
-wxAnimationDisposal wxGIFDecoder::GetDisposalMethod(size_t frame) const
+wxAnimationDisposal wxGIFDecoder::GetDisposalMethod(unsigned int frame) const
{
return GetFrame(frame)->disposal;
}
-long wxGIFDecoder::GetDelay(size_t frame) const
+long wxGIFDecoder::GetDelay(unsigned int frame) const
{
return GetFrame(frame)->delay;
}
-wxColour wxGIFDecoder::GetTransparentColour(size_t frame) const
+wxColour wxGIFDecoder::GetTransparentColour(unsigned int frame) const
{
unsigned char *pal = GetFrame(frame)->pal;
int n = GetFrame(frame)->transparent;
pal[n*3 + 2]);
}
-unsigned char* wxGIFDecoder::GetData(size_t frame) const { return (GetFrame(frame)->p); }
-unsigned char* wxGIFDecoder::GetPalette(size_t frame) const { return (GetFrame(frame)->pal); }
-unsigned int wxGIFDecoder::GetNcolours(size_t frame) const { return (GetFrame(frame)->ncolours); }
-int wxGIFDecoder::GetTransparentColourIndex(size_t frame) const { return (GetFrame(frame)->transparent); }
+unsigned char* wxGIFDecoder::GetData(unsigned int frame) const { return (GetFrame(frame)->p); }
+unsigned char* wxGIFDecoder::GetPalette(unsigned int frame) const { return (GetFrame(frame)->pal); }
+unsigned int wxGIFDecoder::GetNcolours(unsigned int frame) const { return (GetFrame(frame)->ncolours); }
+int wxGIFDecoder::GetTransparentColourIndex(unsigned int frame) const { return (GetFrame(frame)->transparent); }
//
int wxGIFDecoder::getcode(wxInputStream& stream, int bits, int ab_fin)
{
- unsigned int mask; /* bit mask */
- unsigned int code; /* code (result) */
+ unsigned int mask; // bit mask
+ unsigned int code; // code (result)
- /* get remaining bits from last byte read */
+ // get remaining bits from last byte read
mask = (1 << bits) - 1;
code = (m_lastbyte >> (8 - m_restbits)) & mask;
- /* keep reading new bytes while needed */
+ // keep reading new bytes while needed
while (bits > m_restbits)
{
- /* if no bytes left in this block, read the next block */
+ // if no bytes left in this block, read the next block
if (m_restbyte == 0)
{
- m_restbyte = (unsigned char)stream.GetC();
+ m_restbyte = stream.GetC();
/* Some encoders are a bit broken: instead of issuing
* an end-of-image symbol (ab_fin) they come up with
break;
}
- /* prefetch data */
+ // prefetch data
stream.Read((void *) m_buffer, m_restbyte);
if (stream.LastRead() != m_restbyte)
{
m_bufp = m_buffer;
}
- /* read next byte and isolate the bits we need */
+ // read next byte and isolate the bits we need
m_lastbyte = (unsigned char) (*m_bufp++);
mask = (1 << (bits - m_restbits)) - 1;
code = code + ((m_lastbyte & mask) << m_restbits);
m_restbyte--;
- /* adjust total number of bits extracted from the buffer */
+ // adjust total number of bits extracted from the buffer
m_restbits = m_restbits + 8;
}
- /* find number of bits remaining for next code */
+ // find number of bits remaining for next code
m_restbits = (m_restbits - bits);
return code;
// is 'bits'. Supports interlaced images (interl == 1).
// Returns wxGIF_OK (== 0) on success, or an error code if something
// fails (see header file for details)
-wxGIFErrorCode wxGIFDecoder::dgif(wxInputStream& stream, GIFImage *img, int interl, int bits)
+wxGIFErrorCode
+wxGIFDecoder::dgif(wxInputStream& stream, GIFImage *img, int interl, int bits)
{
static const int allocSize = 4096 + 1;
- int *ab_prefix = new int[allocSize]; /* alphabet (prefixes) */
+ int *ab_prefix = new int[allocSize]; // alphabet (prefixes)
if (ab_prefix == NULL)
{
return wxGIF_MEMERR;
}
- int *ab_tail = new int[allocSize]; /* alphabet (tails) */
+ int *ab_tail = new int[allocSize]; // alphabet (tails)
if (ab_tail == NULL)
{
delete[] ab_prefix;
return wxGIF_MEMERR;
}
- int *stack = new int[allocSize]; /* decompression stack */
+ int *stack = new int[allocSize]; // decompression stack
if (stack == NULL)
{
delete[] ab_prefix;
return wxGIF_MEMERR;
}
- int ab_clr; /* clear code */
- int ab_fin; /* end of info code */
- int ab_bits; /* actual symbol width, in bits */
- int ab_free; /* first free position in alphabet */
- int ab_max; /* last possible character in alphabet */
- int pass; /* pass number in interlaced images */
- int pos; /* index into decompresion stack */
- unsigned int x, y; /* position in image buffer */
+ int ab_clr; // clear code
+ int ab_fin; // end of info code
+ int ab_bits; // actual symbol width, in bits
+ int ab_free; // first free position in alphabet
+ int ab_max; // last possible character in alphabet
+ int pass; // pass number in interlaced images
+ int pos; // index into decompresion stack
+ unsigned int x, y; // position in image buffer
int code, readcode, lastcode, abcabca;
- /* these won't change */
+ // these won't change
ab_clr = (1 << bits);
ab_fin = (1 << bits) + 1;
- /* these will change through the decompression proccess */
+ // these will change through the decompression process
ab_bits = bits + 1;
ab_free = (1 << bits) + 2;
ab_max = (1 << ab_bits) - 1;
pass = 1;
pos = x = y = 0;
- /* reset decoder vars */
+ // reset decoder vars
m_restbits = 0;
m_restbyte = 0;
m_lastbyte = 0;
do
{
- /* get next code */
+ // get next code
readcode = code = getcode(stream, ab_bits, ab_fin);
- /* end of image? */
+ // end of image?
if (code == ab_fin) break;
- /* reset alphabet? */
+ // reset alphabet?
if (code == ab_clr)
{
- /* reset main variables */
+ // reset main variables
ab_bits = bits + 1;
ab_free = (1 << bits) + 2;
ab_max = (1 << ab_bits) - 1;
lastcode = -1;
abcabca = -1;
- /* skip to next code */
+ // skip to next code
continue;
}
- /* unknown code: special case (like in ABCABCA) */
+ // unknown code: special case (like in ABCABCA)
if (code >= ab_free)
{
- code = lastcode; /* take last string */
- stack[pos++] = abcabca; /* add first character */
+ code = lastcode; // take last string
+ stack[pos++] = abcabca; // add first character
}
- /* build the string for this code in the stack */
+ // build the string for this code in the stack
while (code > ab_clr)
{
stack[pos++] = ab_tail[code];
return wxGIF_INVFORMAT;
}
- stack[pos] = code; /* push last code into the stack */
- abcabca = code; /* save for special case */
+ stack[pos] = code; // push last code into the stack
+ abcabca = code; // save for special case
- /* make new entry in alphabet (only if NOT just cleared) */
+ // make new entry in alphabet (only if NOT just cleared)
if (lastcode != -1)
{
// Normally, after the alphabet is full and can't grow any
}
}
- /* dump stack data to the image buffer */
+ // dump stack data to the image buffer
while (pos >= 0)
{
(img->p)[x + (y * (img->w))] = (char) stack[pos];
if (interl)
{
- /* support for interlaced images */
+ // support for interlaced images
switch (pass)
{
case 1: y += 8; break;
}
else
{
- /* non-interlaced */
+ // non-interlaced
y++;
/*
Normally image decoding is finished when an End of Information code is
// CanRead:
// Returns true if the file looks like a valid GIF, false otherwise.
//
-bool wxGIFDecoder::CanRead(wxInputStream &stream) const
+bool wxGIFDecoder::DoCanRead(wxInputStream &stream) const
{
unsigned char buf[3];
if ( !stream.Read(buf, WXSIZEOF(buf)) )
return false;
- stream.SeekI(-(wxFileOffset)WXSIZEOF(buf), wxFromCurrent);
-
return memcmp(buf, "GIF", WXSIZEOF(buf)) == 0;
}
wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
{
unsigned int global_ncolors = 0;
- int bits, interl, transparent, i;
+ int bits, interl, i;
wxAnimationDisposal disposal;
long size;
long delay;
unsigned char buf[16];
bool anim = true;
- /* check GIF signature */
+ // check GIF signature
if (!CanRead(stream))
return wxGIF_INVFORMAT;
- /* check for animated GIF support (ver. >= 89a) */
+ // check for animated GIF support (ver. >= 89a)
- static const size_t headerSize = (3 + 3);
+ static const unsigned int headerSize = (3 + 3);
stream.Read(buf, headerSize);
if (stream.LastRead() != headerSize)
{
anim = false;
}
- /* read logical screen descriptor block (LSDB) */
- static const size_t lsdbSize = (2 + 2 + 1 + 1 + 1);
+ // read logical screen descriptor block (LSDB)
+ static const unsigned int lsdbSize = (2 + 2 + 1 + 1 + 1);
stream.Read(buf, lsdbSize);
if (stream.LastRead() != lsdbSize)
{
m_szAnimation.SetWidth( buf[0] + 256 * buf[1] );
m_szAnimation.SetHeight( buf[2] + 256 * buf[3] );
- if ((m_szAnimation.GetWidth() == 0) || (m_szAnimation.GetHeight() == 0))
+ if (anim && ((m_szAnimation.GetWidth() == 0) || (m_szAnimation.GetHeight() == 0)))
{
return wxGIF_INVFORMAT;
}
- /* load global color map if available */
+ // load global color map if available
if ((buf[4] & 0x80) == 0x80)
{
int backgroundColIndex = buf[5];
global_ncolors = 2 << (buf[4] & 0x07);
- size_t numBytes = 3 * global_ncolors;
+ unsigned int numBytes = 3 * global_ncolors;
stream.Read(pal, numBytes);
if (stream.LastRead() != numBytes)
{
pal[backgroundColIndex*3 + 2]);
}
- /* transparent colour, disposal method and delay default to unused */
- transparent = -1;
+ // transparent colour, disposal method and delay default to unused
+ int transparent = -1;
disposal = wxANIM_UNSPECIFIED;
delay = -1;
+ wxString comment;
bool done = false;
while (!done)
{
- type = (unsigned char)stream.GetC();
+ type = stream.GetC();
/*
If the end of file has been reached (or an error) and a ";"
- (0x3B) hasn't been encountered yet, exit the loop. (Without this
+ (GIF_MARKER_ENDOFDATA) hasn't been encountered yet, exit the loop. (Without this
check the while loop would loop endlessly.) Later on, in the next while
loop, the file will be treated as being truncated (But still
be decoded as far as possible). returning wxGIF_TRUNCATED is not
break; // Alternative : "return wxGIF_INVFORMAT;"
}
- /* end of data? */
- if (type == 0x3B)
+ switch (type)
{
- done = true;
- }
- else
- /* extension block? */
- if (type == 0x21)
- {
- if (((unsigned char)stream.GetC()) == 0xF9)
- /* graphics control extension, parse it */
- {
- static const size_t gceSize = 6;
- stream.Read(buf, gceSize);
- if (stream.LastRead() != gceSize)
+ case GIF_MARKER_ENDOFDATA:
+ done = true;
+ break;
+ case GIF_MARKER_EXT:
+ switch (stream.GetC())
{
- Destroy();
- return wxGIF_INVFORMAT;
- }
+ case GIF_MARKER_EXT_GRAPHICS_CONTROL:
+ {
+ // graphics control extension, parse it
- /* read delay and convert from 1/100 of a second to ms */
- delay = 10 * (buf[2] + 256 * buf[3]);
+ static const unsigned int gceSize = 6;
+ stream.Read(buf, gceSize);
+ if (stream.LastRead() != gceSize)
+ {
+ Destroy();
+ return wxGIF_INVFORMAT;
+ }
- /* read transparent colour index, if used */
- if (buf[1] & 0x01)
- transparent = buf[4];
+ // read delay and convert from 1/100 of a second to ms
+ delay = 10 * (buf[2] + 256 * buf[3]);
- /* read disposal method */
- disposal = (wxAnimationDisposal)(((buf[1] & 0x1C) >> 2) - 1);
- }
- else
- /* other extension, skip */
- {
- while ((i = (unsigned char)stream.GetC()) != 0)
- {
- if (stream.Eof() || (stream.LastRead() == 0))
+ // read transparent colour index, if used
+ transparent = buf[1] & 0x01 ? buf[4] : -1;
+
+ // read disposal method
+ disposal = (wxAnimationDisposal)(((buf[1] & 0x1C) >> 2) - 1);
+ break;
+ }
+ case GIF_MARKER_EXT_COMMENT:
{
- done = true;
+ int len = stream.GetC();
+ while (len)
+ {
+ if ( stream.Eof() )
+ {
+ done = true;
+ break;
+ }
+
+ wxCharBuffer charbuf(len);
+ stream.Read(charbuf.data(), len);
+ if ( (int) stream.LastRead() != len )
+ {
+ done = true;
+ break;
+ }
+
+ comment += wxConvertMB2WX(charbuf.data());
+
+ len = stream.GetC();
+ }
+
break;
}
- stream.SeekI(i, wxFromCurrent);
+ default:
+ // other extension, skip
+ while ((i = stream.GetC()) != 0)
+ {
+ if (stream.Eof() || (stream.LastRead() == 0) ||
+ stream.SeekI(i, wxFromCurrent) == wxInvalidOffset)
+ {
+ done = true;
+ break;
+ }
+ }
+ break;
}
- }
- }
- else
- /* image descriptor block? */
- if (type == 0x2C)
- {
- /* allocate memory for IMAGEN struct */
- GIFImage *pimg = new GIFImage();
-
- if (pimg == NULL)
+ break;
+ case GIF_MARKER_SEP:
{
- Destroy();
- return wxGIF_MEMERR;
- }
+ // allocate memory for IMAGEN struct
+ GIFImagePtr pimg(new GIFImage());
- /* fill in the data */
- static const size_t idbSize = (2 + 2 + 2 + 2 + 1);
- stream.Read(buf, idbSize);
- if (stream.LastRead() != idbSize)
- {
- Destroy();
- return wxGIF_INVFORMAT;
- }
+ wxScopeGuard guardDestroy = wxMakeObjGuard(*this, &wxGIFDecoder::Destroy);
- pimg->left = buf[0] + 256 * buf[1];
- pimg->top = buf[2] + 256 * buf[3];
-/*
- pimg->left = buf[4] + 256 * buf[5];
- pimg->top = buf[4] + 256 * buf[5];
-*/
- pimg->w = buf[4] + 256 * buf[5];
- pimg->h = buf[6] + 256 * buf[7];
+ if ( !pimg.get() )
+ return wxGIF_MEMERR;
- if ((pimg->w == 0) || (pimg->w > (unsigned int)m_szAnimation.GetWidth()) ||
- (pimg->h == 0) || (pimg->h > (unsigned int)m_szAnimation.GetHeight()))
- {
- Destroy();
- return wxGIF_INVFORMAT;
- }
+ // fill in the data
+ static const unsigned int idbSize = (2 + 2 + 2 + 2 + 1);
+ stream.Read(buf, idbSize);
+ if (stream.LastRead() != idbSize)
+ return wxGIF_INVFORMAT;
+
+ pimg->comment = comment;
+ comment.clear();
+ pimg->left = buf[0] + 256 * buf[1];
+ pimg->top = buf[2] + 256 * buf[3];
+ /*
+ pimg->left = buf[4] + 256 * buf[5];
+ pimg->top = buf[4] + 256 * buf[5];
+ */
+ pimg->w = buf[4] + 256 * buf[5];
+ pimg->h = buf[6] + 256 * buf[7];
+
+ if ( anim )
+ {
+ // some GIF images specify incorrect animation size but we can
+ // still open them if we fix up the animation size, see #9465
+ if ( m_nFrames == 0 )
+ {
+ if ( pimg->w > (unsigned)m_szAnimation.x )
+ m_szAnimation.x = pimg->w;
+ if ( pimg->h > (unsigned)m_szAnimation.y )
+ m_szAnimation.y = pimg->h;
+ }
+ else // subsequent frames
+ {
+ // check that we have valid size
+ if ( (!pimg->w || pimg->w > (unsigned)m_szAnimation.x) ||
+ (!pimg->h || pimg->h > (unsigned)m_szAnimation.y) )
+ {
+ wxLogError(_("Incorrect GIF frame size (%u, %d) for "
+ "the frame #%u"),
+ pimg->w, pimg->h, m_nFrames);
+ return wxGIF_INVFORMAT;
+ }
+ }
+ }
- interl = ((buf[8] & 0x40)? 1 : 0);
- size = pimg->w * pimg->h;
+ interl = ((buf[8] & 0x40)? 1 : 0);
+ size = pimg->w * pimg->h;
- pimg->transparent = transparent;
- pimg->disposal = disposal;
- pimg->delay = delay;
+ pimg->transparent = transparent;
+ pimg->disposal = disposal;
+ pimg->delay = delay;
- /* allocate memory for image and palette */
- pimg->p = (unsigned char *) malloc((size_t)size);
- pimg->pal = (unsigned char *) malloc(768);
+ // allocate memory for image and palette
+ pimg->p = (unsigned char *) malloc((unsigned int)size);
+ pimg->pal = (unsigned char *) malloc(768);
- if ((!pimg->p) || (!pimg->pal))
- {
- Destroy();
- return wxGIF_MEMERR;
- }
+ if ((!pimg->p) || (!pimg->pal))
+ return wxGIF_MEMERR;
- /* load local color map if available, else use global map */
- if ((buf[8] & 0x80) == 0x80)
- {
- unsigned int local_ncolors = 2 << (buf[8] & 0x07);
- size_t numBytes = 3 * local_ncolors;
- stream.Read(pimg->pal, numBytes);
- pimg->ncolours = local_ncolors;
- if (stream.LastRead() != numBytes)
+ // load local color map if available, else use global map
+ if ((buf[8] & 0x80) == 0x80)
{
- Destroy();
- return wxGIF_INVFORMAT;
+ unsigned int local_ncolors = 2 << (buf[8] & 0x07);
+ unsigned int numBytes = 3 * local_ncolors;
+ stream.Read(pimg->pal, numBytes);
+ pimg->ncolours = local_ncolors;
+ if (stream.LastRead() != numBytes)
+ return wxGIF_INVFORMAT;
+ }
+ else
+ {
+ memcpy(pimg->pal, pal, 768);
+ pimg->ncolours = global_ncolors;
}
- }
- else
- {
- memcpy(pimg->pal, pal, 768);
- pimg->ncolours = global_ncolors;
- }
- /* get initial code size from first byte in raster data */
- bits = (unsigned char)stream.GetC();
- if (bits == 0)
- {
- Destroy();
- return wxGIF_INVFORMAT;
- }
+ // get initial code size from first byte in raster data
+ bits = stream.GetC();
+ if (bits == 0)
+ return wxGIF_INVFORMAT;
- /* decode image */
- wxGIFErrorCode result = dgif(stream, pimg, interl, bits);
- if (result != wxGIF_OK)
- {
- Destroy();
- return result;
- }
+ // decode image
+ wxGIFErrorCode result = dgif(stream, pimg.get(), interl, bits);
+ if (result != wxGIF_OK)
+ return result;
- /* add the image to our frame array */
- m_frames.Add((void*)pimg);
- m_nFrames++;
+ guardDestroy.Dismiss();
- /* if this is not an animated GIF, exit after first image */
- if (!anim)
- done = true;
+ // add the image to our frame array
+ m_frames.Add(pimg.release());
+ m_nFrames++;
+
+ // if this is not an animated GIF, exit after first image
+ if (!anim)
+ done = true;
+ break;
+ }
}
}
return wxGIF_INVFORMAT;
}
- /* try to read to the end of the stream */
- while (type != 0x3B)
+ // try to read to the end of the stream
+ while (type != GIF_MARKER_ENDOFDATA)
{
if (!stream.IsOk())
return wxGIF_TRUNCATED;
- type = (unsigned char)stream.GetC();
+ type = stream.GetC();
- if (type == 0x21)
+ switch (type)
{
- /* extension type */
- (void) stream.GetC();
+ case GIF_MARKER_EXT:
+ // extension type
+ (void) stream.GetC();
- /* skip all data */
- while ((i = (unsigned char)stream.GetC()) != 0)
+ // skip all data
+ while ((i = stream.GetC()) != 0)
+ {
+ if (stream.Eof() || (stream.LastRead() == 0) ||
+ stream.SeekI(i, wxFromCurrent) == wxInvalidOffset)
+ {
+ Destroy();
+ return wxGIF_INVFORMAT;
+ }
+ }
+ break;
+ case GIF_MARKER_SEP:
{
- if (stream.Eof() || (stream.LastRead() == 0))
+ // image descriptor block
+ static const unsigned int idbSize = (2 + 2 + 2 + 2 + 1);
+ stream.Read(buf, idbSize);
+ if (stream.LastRead() != idbSize)
{
Destroy();
return wxGIF_INVFORMAT;
}
- stream.SeekI(i, wxFromCurrent);
- }
- }
- else if (type == 0x2C)
- {
- /* image descriptor block */
- static const size_t idbSize = (2 + 2 + 2 + 2 + 1);
- stream.Read(buf, idbSize);
- if (stream.LastRead() != idbSize)
- {
- Destroy();
- return wxGIF_INVFORMAT;
- }
- /* local color map */
- if ((buf[8] & 0x80) == 0x80)
- {
- unsigned int local_ncolors = 2 << (buf[8] & 0x07);
- wxFileOffset pos = stream.TellI();
- wxFileOffset numBytes = 3 * local_ncolors;
- stream.SeekI(numBytes, wxFromCurrent);
- }
-
- /* initial code size */
- (void) stream.GetC();
- if (stream.Eof() || (stream.LastRead() == 0))
- {
- Destroy();
- return wxGIF_INVFORMAT;
- }
+ // local color map
+ if ((buf[8] & 0x80) == 0x80)
+ {
+ unsigned int local_ncolors = 2 << (buf[8] & 0x07);
+ wxFileOffset numBytes = 3 * local_ncolors;
+ if (stream.SeekI(numBytes, wxFromCurrent) == wxInvalidOffset)
+ {
+ Destroy();
+ return wxGIF_INVFORMAT;
+ }
+ }
- /* skip all data */
- while ((i = (unsigned char)stream.GetC()) != 0)
- {
+ // initial code size
+ (void) stream.GetC();
if (stream.Eof() || (stream.LastRead() == 0))
{
Destroy();
return wxGIF_INVFORMAT;
}
- stream.SeekI(i, wxFromCurrent);
+
+ // skip all data
+ while ((i = stream.GetC()) != 0)
+ {
+ if (stream.Eof() || (stream.LastRead() == 0) ||
+ stream.SeekI(i, wxFromCurrent) == wxInvalidOffset)
+ {
+ Destroy();
+ return wxGIF_INVFORMAT;
+ }
+ }
+ break;
}
- }
- else if ((type != 0x3B) && (type != 00)) /* testing */
- {
- /* images are OK, but couldn't read to the end of the stream */
- return wxGIF_TRUNCATED;
+ default:
+ if ((type != GIF_MARKER_ENDOFDATA) && (type != 00)) // testing
+ {
+ // images are OK, but couldn't read to the end of the stream
+ return wxGIF_TRUNCATED;
+ }
+ break;
}
}
projects / wxWidgets.git / blobdiff